The Avengers star was set to play 1970s Pittsburgh crime boss Dante "Tex" Gill, who was born Jean Gill, in Rub & Tug.
But she was criticised by those who said the role should have gone to a transgender actor.
"I've learned a lot from the community since making my first statement," Johansson told Out magazine.
"While I would have loved the opportunity to bring Dante's story and transition to life, I understand why many feel he should be portrayed by a transgender person."
"I am thankful that this casting debate... has sparked a larger conversation about diversity and representation in film," she added.
The original announcement was met with intense criticism and some said it showed the limited opportunities given to transgender actors.
Trace Lysette, who stars in the Amazon series Transparent, said it was representative of a wider problem in Hollywood.
"I wouldn't be as upset if I was getting in the same rooms as Jennifer Lawrence and Scarlett for cis roles, but we know that's not the case," she tweeted. "A mess."
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